Disco Floor’s are passé. [dennis1a4] turned them upside down and built an awesome RGB LED ceiling display using some simple hardware and a lot of elbow grease. His main room ceiling was exactly 32 ft x 20 ft and using 2 sq. ft tiles, he figured he could make a nice grid using 160 WS2812B RGB LEDs. A Teensy mounted in the ceiling does all the heavy lifting, with two serial Bluetooth modules connected to it. These get connected to two Bluetooth enabled NES game controllers. Each of the NES controller is stuffed with an Arduino Pro Mini, a Bluetooth module, Li-Ion battery and a USB charge controller.
Bluetooth is in non-secure mode, allowing him to connect to the Teensy, and control the LEDs, from other devices besides the NES controllers. The Teensy is mounted at the centre of the ceiling to ensure a good Bluetooth link. Programming required a lot of thought and time but he did manage to include animations as well as popular games such as Snake and Tetris.
The hard part was wiring up all of the 160 LED pixels. Instead of mounting the 5050 SMD LED’s on PCBs, [dennis1a4] wired them all up “dead bug” style. Each pixel has one LED, a 100nF decoupling capacitor, and 91 ohm resistors in series with the Data In and Data Out pins – these apparently help prevent ‘ringing’ on the data bus. Check the video for his radical soldering method. Each SMD LED was clamped in a machine shop vice, and the other three parts with their leads preformed were soldered directly to the LED pins.
The other tedious task was planning and laying out the wiring harness. Sets of 10 LEDs were first wired up on the shop bench. He then tacked them up to the ceiling and soldered them to the 14 gauge main harness. The final part was to put up the suspended ceiling and close the 2 sq. ft. grids with opaque plastic.
[dennis1a4] did some trials to figure out the right distance between each LED and the panel to make sure they were illuminated fully without a lot of light bleeding in to adjacent panels. This allowed him to get away without using baffles between the tiles.
Check out the video to see a cool time-lapse of the whole build.
Continue reading “RGB LED Ceiling Display”
Life down on the farm isn’t easy, and a little technology can go a long way to making things easier for the farmer. It’ll be a while before any farmer can kick back on the beach and run his place from a smartphone, but that’s clearly the direction things are heading with this small farm automation project.
[Vince]’s livestock appears to consist of chickens and sheep at this point, and the fact that they share housing helped him to deploy some tech for both species. The chickens got an automated door that lets them out in the morning and shuts them in safely once they’ve returned to roost for the night – important protection against predators. The door is hoisted by a Somfy window-treatment motor, which seems a little on the overkill side to us; a thrift-store electric drill and a homebrew drum might have worked too. A Teensy with an RTC opens and closes the door according to sunrise and sunset times, and temperature and humidity sensors provide feedback on conditions inside the coop. The sheep benefit from a PTZ webcam to keep an eye on their mischief, and the whole thing is controlled by a custom web interface from [Vince]’s smartphone.
There’s just something about automating chicken coop doors that seems to inspire hackers; check out this nice self-locking design. As for [Vince]’s farm, it looks like his system has a lot of room for expansion – food and water status would be a great next step. We’re looking forward to seeing where he goes from here.
A few weeks ago, we took a look at the best badge hacks at the Hackaday Supercon. These were the best badge hacks anyone has ever seen – including what comes out of DEF CON and the SDR badge from the latest CCC. I’m ascribing this entirely to the free-form nature of the badge; give people a blank canvas and you’re sure to get a diverse field of builds. Now it’s time to take a look at the cream of the crop, hear what the jolly wrencher sounds like, and how to put 1000 Volts in a badge.
There were three categories for the badge hacking competition at the SuperCon – best deadbug, best blinky, and most over the top. A surprising number of people managed to solder, glue, and tape some components to a the piece of FR4 we used as a conference badge, but in the end, only three would win.
Continue reading “The Best Badges Of The SuperCon”
[John] has an interesting, if old piece of tech sitting on his workbench. It’s an Ohio Scientific C3-8P computer from the late 70s by way of a few garages, basements, and attics. As with most tech of this vintage, there are some problems, and [John] found debugging a little frustrating without the ability to trace and watch the programs. He needed a logic analyzer, and found one in an unlikely piece of hardware. [John] built one using a Teensy microcontroller, and further refinement of this project could turn it into a full in-system emulator.
The old Ohio Scientific computer [John] is trying to bring back from the dead is based on the 6502 CPU. That’s sixteen address lines to monitor, eight data lines, and four control lines. These were wired directly to a Teensy 3.1.
Reading and controlling all the signals from a 6502 is a task that falls to Linux. A command line program controls the Teensy and is capable of reading memory, setting trigger addresses, dumping the entire address space to a file, or just recording the last 5,000 clock cycles. This kind of tech existed back in the late 70s and early 80s. It also cost a fortune. Now, with a $20 Teensy and probably another $30 in ribbon cables and test clips, anyone can build a logic analyser for a very old computer system.
Continue reading “A Teensy Logic Analyzer For A 6502”
A few days ago, we saw a project that used a Teensy to build a Universal 2nd Factor (U2F) key. While this project was just an experiment in how to implement U2F on any ‘ol microcontroller, and the creator admitted it wasn’t very secure, the comments for that post said otherwise: “making your own thing is the ONLY way to be secure,” read the comments.
In a stunning turn of events, writing comments on a blog post doesn’t mean you know what you’re talking about. It turns out, to perform a security analysis of a system, you need to look at the code. Shocking, yes, but [makomk] took a good, hard look at the code and found it was horribly broken.
The critical error of the Teensy U2F key crypto is simply how U2F is performed. During authentication, the device sends the U2F key handle to whatever service is trying to authenticating it. Because the key in the Teensy implementation is only ‘encrypted’ with XOR, it only takes 256 signing requests to recover the private key.
The original experimentation with using the Teensy as a U2F key was an educational endeavor, and it was never meant to be used by anyone. The attack on this small lesson in security is interesting, though, and [makomk] wrote a proof of concept that demonstrates his attack. This could be used to perform attacks from a remote server, but hopefully that won’t happen, because the original code should never be used in the wild.
It used to be that you had to spend real money to get an alternative controller for your electronic musical arsenal. These days, with cheap microcontrollers and easily-accessible free software libraries, you can do something awesome for pocket change. But that doesn’t mean that you can’t make a sexy, functional piece of art along the way! [Jan Godde] did just that with his cleverly named Wooden Sensor Box With Two Rotary Disks. (If you’ve got a better name for this thing, toss it in the comments.)
From what we can see, the box has two potentiometer sliders, two touch-sensitive potentiometers, two force sensitive resistors, a slew of knobs, and a whole bunch of (capacitive?) touch points. In short, a ton of continuous controllers of all sizes and shapes in an aesthetic case. But stealing the show, and giving the device its name, are two platters from old hard drives that serve as jog wheels.
As shown in the video below the break, the two jog wheels are covered with alternating stripes on the underside. Each platter has a dedicated pair of IR LEDs and photodetectors underneath serving as a quadrature encoder that allows [Jan] to tell which direction the platters are rotating, and how far.
Continue reading “Two Turntables and No Microphone”
Last month, GitHub users were able to buy a special edition Universal 2nd Factor (U2F) security key for just five bucks. [Yohanes] bought two, but wondered if he could bring U2F to other microcontrolled devices. he ended up building a U2F key with a Teensy LC, and in the process brought U2F to the unwashed masses.
Universal 2nd Factor is exactly what it says on the tin: it doesn’t replace your password, but it does provide a little bit of extra verification to prove that the person logging into an account is indeed the person that should. Currently, Google (through Gmail and Google Drive), Github, Dropbox, and even WordPress (through a plugin) support U2F devices, so a tiny USB key that’s able to provide U2F is a very useful device.
After digging into the U2F specification [Yohanes] found the Teensy LC would be a perfect platform for experimentation. A U2F device is just a USB HID device, which the Teensy handles in spades. A handy library takes on ECC for both AVR and ARM platforms and [Yohanes’] finished U2F implementation is able to turn the Teensy LC into something GitHub was selling for $5.
It should be noted that doing anything related to security by yourself, with your own code is dumb and should not be considered secure. Additionally, [Yohanes] didn’t want to solder a button to his Teensy LC, so he implemented everything without a button press, which is also insecure. The ‘key handle’ is just XOR encryption with a fixed key, which is also insecure. Despite this, it’s still an interesting project and we’re happy [Yohanes] shared it with us.